Morphometry of submucous and myenteric esophagic plexus of dogs experimentally reinfected with Trypanosoma cruzi

We carried out a morphometric study of the esophagus of cross-bred dogs experimentally infected or consecutively reinfected with Trypanosoma cruzi 147 and SC-1 strains, in order to verify denervation and/or neuronal hypertrophy in the intramural plexus. The animals were sacrificed in the chronic stage, 38 months after the initial infection. Neither nests of amastigotes, nor myositis or ganglionitis, were observed in all third inferior portions of esophageal rings analyzed. No nerve cell was identified in the submucous of this organ. There was no significant difference (p>0.05) between the number, maximum diameter, perimeter, or area and volume of the nerve cells of the myenteric plexus of infected and/or reinfected dogs and of the non-infected ones. In view of these results we may conclude that the 147 and SC-1 strains have little neurotropism and do not determine denervation and/or hypertrophy in the intramural esophageal plexuses in the animals studied, independent of the reinfections

Estudo quantitativo e qualitativo dos plexos de Auerbach e Meissner do esôfago de cäes inoculados com o Trypanosoma cruzi / A quantitative and qualitative study of the Auerbach and Meissner plexus in dogs inoculated with Trypanosoma cruzi

A quantitative and qualitative study was conducted on the Auerbach and Meissner plexuses of the esophagus of four chagasic dogs sacrificed during the acute phase of infection. Ganglionitis and periganglionitis of the Auerbach plexus ranged from mild to moderate and induced significant neuronal lesions, especially in two animals. The ganglions of the Meissner plexus were observed in small number which did not permit any analysis. Mild or moderate myositis was observed mainly in the lower third of the esophagus and was rarely associated with amastigote nests. Ganglion and neuron counts did not demonstrate denervation. Although the formation of megaesophagus was not induced in any dog, lesions of the Auerbach plexus and myocells of the esophagus were observed during the acute phase of chagasic infection. To our knowledge, this is the first systematic quantitative and qualitative study of the Auerbach and Meissner plexuses of the esophagus in experimental trypanosomiasis cruzi.